Did this ever get added?
Frames to go (1,2,3,4,5,4,3,2) etc.
I seem to recall a distant conversation about it, but before I make my own animation function, I thought I'd check if it exists undocumented.

it may be possible with the start and end frame
PlaySprite( iSpriteIndex, fFps, iLoop, iFromFrame, iToFrame )
play from 1 to lastframe
check if playing
play lastframe to 1
repeat

The cheap, entirely non-optimal, and resource-intensive way would be to build the ping pong right into your frame strip and just play the animation normally.

You could do that with AddSpriteAnimationFrame()

both better solutions than mine
I guess sometimes its not being able to add the animations yourself

It's fine to just do the animation handler myself. I just seemed to remember a conversation about ping-pong animation and wondered if it was undocumented.
As it turns out, my animation uses multiple sets of 8 frames and switching between sets, I use a different count/offset.
No biggie, just wondered if it was ever put in.